Stabilized hydrogen peroxide solutions

ABSTRACT

The present invention is directed to a stabilized hydrogen peroxide solution containing stabilizers that maintain relatively high hydrogen peroxide stability in both concentrated form and when formulated into a cleaning solution that has a pH above 6 and contains components that normally would have a destabilizing effect on the hydrogen peroxide. The stabilizers include a first cyclic amino methane diphosphonic acid compound stabilizer in combination with a second phosphonic acid based stabilizer (different from the cyclic amino methane diphosphonic acid compound), wherein the weight ratio of the first stabilizer to the second stabilizer is at least about 2:1.

This application is a national stage filing under 35 U.S.C. §371 ofPCT/US2007/025494, filed Dec. 13, 2007, the contents of which areincorporated herein by reference in their entirety.

FIELD OF THE INVENTION

The field of the invention relates to stabilization of hydrogenperoxide. More particularly, it relates to hydrogen peroxide solutionscontaining specific stabilizers and processes for preparing formulationscontaining a stabilized hydrogen peroxide.

BACKGROUND OF THE INVENTION

Stabilizers are normally added to hydrogen peroxide solutions to combatdecomposition due to trace impurities, mainly dissolved metals. Thesecompounds are usually sequestering agents and can take many forms. Manytypes of compounds have been used to fill this function, such as diols,quinones, stannate salts, pyrophosphates, various aromatic compounds andamino carboxylic acids salts. However, many of the previously suggestedcompounds have various issues and challenges associated with them, suchas toxicity, environmental impact and poor performance.

Examples of specific compounds that have been suggested for use insolutions to protect against hydrogen peroxide decomposition includesodium phenolsulfate; sodium stannate; N,N-lower alkyl aniline, sulfamicacid, sulfolane, and dinormal lower alkyl sulfones and sulfoxides;phosphonic acids and their salts; acrylic acid polymers; polyphosphates;polyamino polyphosphonic acids and/or their salts; and specificcombinations (or blends) of such compounds. However, in addition totoxicity and environmental impact concerns, many of these suggestedcompounds or blends have other drawbacks. For example, use of thespecific stabilizer(s) either require specific conditions to provideadequate hydrogen peroxide stability, such as specific pH levels, e.g.,acidic conditions, or relatively low hydrogen peroxide concentrations,or have poor stability performance. The poor stability performance caneither be poor stability performance generally or poor stabilityperformance in specific formulations that contain other destabilizingcomponents, e.g., surfactants.

In addition, hydrogen peroxide has been used widely as an ingredient invarious cleaning solutions. Many such cleaning solutions require analkali pH and various other ingredients, which have a destabilizingeffect on the hydrogen peroxide, to achieve the desired cleaningperformance. Accordingly, it would be desirable to provide such acleaning solution where the hydrogen peroxide decomposition isminimized.

Despite considerable efforts which have been applied with availablestabilizer compounds to solve the problem, there still exists a need toprovide hydrogen peroxide solutions which are highly stable without theabove mentioned drawbacks.

SUMMARY OF THE INVENTION

The present invention is directed to a stabilized hydrogen peroxidesolution containing stabilizers which avoid the drawbacks associatedwith other stabilizers, as discussed above. The present stabilizedhydrogen peroxide solution maintains relatively high hydrogen peroxidestability in both concentrated form and when formulated into a cleaningsolution that has a pH of 6 or above and contains components thatnormally would have a destabilizing effect on the hydrogen peroxide.

In a first aspect, the invention is directed to a stabilized hydrogenperoxide solution that includes: (a) hydrogen peroxide in an amount fromabout 20 to about 70 wt %, based on the entire solution; (b) a firstcyclic amino methane diphosphonic acid compound stabilizer; (c) a secondphosphonic acid based stabilizer, different from the cyclic aminomethane diphosphonic acid compound stabilizer; and (d) water, whereinthe weight ratio of (b) to (c) is at least about 2:1. As defined morespecifically below, it is to be understood that the cyclic amino methanediphosphonic acid compound stabilizer includes both salts anddecomposition products of the described compound.

Preferably, the cyclic amino methane diphosphonic acid compoundstabilizer corresponds to the following formula:

-   -   wherein R₁ is selected from hydrogen, C₁-C₄ alkyl and phenyl; Q        represents the atoms or chemical bonds necessary to complete a        6-membered ring; and X₁ to X₄, independently from each other,        are selected from hydrogen, alkali metal and ammonium. The        cyclic amino methane diphosphonic acid compound stabilizer is        preferably a morpholino methane diphosphonic acid salt.

In one embodiment, the phosphonic acid based stabilizer (different fromthe cyclic amino methane diphosphonic acid compound stabilizer) containsnitrogen in its structure. Preferably, this phosphonic acid basedstabilizer is an amino phosphonic acid based compound. In oneembodiment, the phosphonic acid based stabilizer contains three or morephosphonic acid groups.

In one embodiment, the phosphonic acid based stabilizer is selected fromthe group consisting of diethylene triamine penta(methylene phosphonic)acid, amino tri(methylene phosphonic) acid, and hexamethylene diaminetetra(methylene phosphonic) acid, their salts, their degradationproducts, and combinations thereof.

In one embodiment, the hydrogen peroxide is present in an amount fromabout 30 to about 60 wt %, based on the entire solution. In anotherembodiment, the hydrogen peroxide is present in an amount from about 35to about 55 wt %, based on the entire solution.

The cyclic amino methane diphosphonic acid compound stabilizer ispreferably present in an amount of from about 0.01 to about 10 wt %,more preferably about 0.1 to about 5 wt %, and most preferably about 0.3to about 1.5 wt %, based on the amount of hydrogen peroxide. The ratioof the first stabilizer to the second stabilizer is preferably in therange from about 2:1 to about 100,000:1, more preferably about 5:1 toabout 5,000:1, and most preferably about 10:1 to about 500:1.

Preferably, the first and second stabilizers are present in amountssufficient to provide a test solution with a hydrogen peroxide stabilityof at least about 50% after 16 hours at about 97° C. and a pH of about9.5 to about 9.6. The test solution is prepared by combining thestabilized hydrogen peroxide solution, in an amount sufficient toprovide the test solution with a starting hydrogen peroxide content ofabout 3 to 3.5 wt %, with a nonionic/cationic surfactant blend in anamount of about 5 wt %, based on the weight of the test solution, andcaustic in an amount to bring the pH of the test solution to about 9.5to 9.6. Preferably, the hydrogen peroxide stability is at least about60% and more preferably at least about 65%.

In one embodiment, the stabilized hydrogen peroxide solution containsless than 10 ppm of metals.

In another aspect, the invention is directed to a cleaning solution thatcontains: (a) hydrogen peroxide; (b) a first cyclic amino methanediphosphonic acid compound stabilizer; (c) a second phosphonic acidbased stabilizer, different from the cyclic amino methane diphosphonicacid compound stabilizer; and (d) a surfactant; wherein the pH of thecleaning solution is above 6 and the weight ratio of (b) to (c) is atleast about 2:1.

The cyclic amino methane diphosphonic acid compound stabilizer and thephosphonic acid based stabilizer (different from the cyclic aminomethane diphosphonic acid compound stabilizer) are preferably the sameas those described above, with respect to the stabilized hydrogenperoxide solution.

The hydrogen peroxide is preferably present in an amount from about 0.1to about 20 wt %, more preferably about 0.3 to about 15 wt %, and mostpreferably about 0.5 to about 8 wt %, based on the entire cleaningsolution. The cyclic amino methane diphosphonic acid compound stabilizerand the phosphonic acid based stabilizer are preferably present in theamounts described above with respect to the stabilized hydrogen peroxidesolution.

The surfactant can be a type selected from the group consisting ofanionic, nonionic, cationic and combinations thereof. In one embodiment,the surfactant is a type selected from the group consisting of anon-ionic surfactant, a cationic surfactant and combinations thereof. Inanother embodiment, the surfactant is an anionic surfactant, preferablyan anionic surfactant having a phenyl sulfonic structure, either aloneor in combination with a non-ionic surfactant.

The cleaning solution can also include other additives selected from thegroup consisting of builders, fragrances, colorants and combinationsthereof. In one embodiment, the builders are selected from the groupconsisting of organic and inorganic salts, such as but not limited toEDTA, sodium chloride, polyphosphates and the like.

In one embodiment, the cleaning solution contains less than 10 ppm ofmetals.

Preferably, the pH of the cleaning solution is in the range of at least6 to about 10.5, more preferably at least 7 to about 10.5 and mostpreferably about 8 to about 10. Preferably, the first and secondstabilizers are present in amounts sufficient to provide the cleaningsolution with a hydrogen peroxide stability of at least about 50%, morepreferably at least about 60%, and most preferably at least about 65%,after 16 hours at about 97° C.

In one preferred embodiment, the hydrogen peroxide is present in anamount from about 0.1 to about 20 wt %, based on the entire cleaningsolution; the first cyclic amino methane diphosphonic acid compoundstabilizer is a morpholino methane diphosphonic acid salt and is presentin an amount from about 0.01 to about 10 wt %, based on the amount ofhydrogen peroxide; and the second phosphonic acid based stabilizer isselected from the group consisting of diethylene triaminepenta(methylene phosphonic) acid, amino tri(methylene phosphonic) acid,and hexamethylene diamine tetra(methylene phosphonic) acid, their salts,their degradation products, and combinations thereof.

In yet another aspect, the invention is directed to a process forpreparing a cleaning solution. The process includes combining astabilized hydrogen peroxide solution (as described above) with asurfactant, water and an alkali agent in an amount to bring the pH ofthe cleaning solution to at least 6, to provide a cleaning solutioncontaining from about 0.5 to about 20 wt % hydrogen peroxide.

Additional objects, advantages and novel features will be apparent tothose skilled in the art upon examination of the description thatfollows.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to a stabilized hydrogen peroxidesolution containing stabilizers that maintain relatively high hydrogenperoxide stability in both concentrated form and when formulated into acleaning solution that has a pH above 6 and contains components thatnormally would have a destabilizing effect on the hydrogen peroxide.

The present invention utilizes a cyclic amino methane diphosphonic acidcompound stabilizer in combination with a phosphonic acid basedstabilizer, other than the cyclic amino methane diphosphonic acidcompound stabilizer.

By the term “cyclic amino methane diphosphonic acid compound stabilizer”is intended to include compounds having a cyclic amino methanediphosphonic acid structure, including compounds in their acid form orsalts thereof, as well as decomposition products of such compounds.

Similarly, by the term “phosphonic acid based stabilizer” is intended toinclude compounds having at least one phosphonic acid group in itsstructure, including compounds in their acid form or salts thereof, aswell as decomposition products of such compounds.

The cyclic amino methane diphosphonic acid compound stabilizer accordingto the invention preferably corresponds to the following formula:

-   -   wherein R₁ is selected from hydrogen, C₁-C₄ alkyl and phenyl; Q        represents the atoms or chemical bonds necessary to complete a        6-membered ring; and X₁ to X₄, independently from each other,        are selected from hydrogen, alkali metal and ammonium. The        6-membered ring preferably includes oxygen in the ring        structure, preferably the oxygen is positioned directly across        from the nitrogen.

The phosphonic acid based stabilizer can include commercially availablecompounds which include a phosphonic acid group in their structure.Non-limiting examples of such stabilizers include1-hydroxy-1,1-ethylidene diphosphonate commercially available as DEQUEST2010, amino trimethylene-phosphonic acid) available as DEQUEST 2000 andDEQUEST 2000LC; amino tri(methylene-phosphonic acid)pentasodium saltavailable as DEQUEST 2006; 1-hydroxyethylene-1,1,-diphosphonic acidcommercially available as DEQUEST 2010;1-hydroxyethylene-1,1,-diphosphonic acid tetrasodium salt available asDEQUEST 2016 and DEQUEST 2016D; ethylene diamine tetra(methylenephosphonic acid) available as DEQUEST 2041; ethylene diaminetetra(methylene phosphonic acid) pentasodium salt available as DEQUEST2046; hexamethylenediamine tetra(methylene phosphonic acid) potassiumsalt available as DEQUEST 2054; diethylenetriamine penta(methylenephosphonic acid) available as DEQUEST 2060S; diethylenetriaminepenta(methylenephosphonic acid)trisodium salt available as DEQUEST2066A; diethylenetriamine penta(methylenephosphonic acid)pentasodiumsalt available as DEQUEST 2066; diethylenetriamine penta(methylenephosphonic acid)pentasodium salt commercially available as DEQUEST2066C2; bis-hexamethylene triaminepenta(methylenephosphonic acid)chloride salt commercially available as DEQUEST 2090A; tetrasodium saltof 1-hydroxy ethyliden (1,1-diphosphonic acid) commercially available asDEQUEST SPE 9528, as well as other materials sold under the DEQUESTtradename, particularly DEQUEST 2086, DEQUEST 3000S, as well as DEQUEST6004.

In one embodiment, the phosphonic acid based stabilizer containsnitrogen in its structure. Preferably, this phosphonic acid basedstabilizer is an amino phosphonic acid based compound. In oneembodiment, the phosphonic acid based stabilizer contains three or morephosphonic acid groups. Preferably, the phosphonic acid based stabilizercontains both nitrogen and three or more phosphonic acid groups in itsstructure.

In a preferred embodiment, the phosphonic acid based stabilizer isselected from the group consisting of diethylene triaminepenta(methylene phosphonic) acid, amino tri(methylene phosphonic) acid,and hexamethylene diamine tetra(methylene phosphonic) acid, their salts,their degradation products, and combinations thereof.

The stabilized hydrogen peroxide solution according to the inventionpreferably includes a cyclic amino (methylene phosphonic acid) salt incombination with at least one phosphonic acid salt (as described above)in amounts sufficient to achieve enhanced hydrogen peroxide stability informulations with pH's over 7. It is believed that the ring structure ofcyclic amino (methylene phosphonic acid) salts gives these compoundssimilar stabilizing attributes to phenols without the attendant negativeenvironmental and toxicity impact.

The cyclic amino methane diphosphonic acid compound stabilizer ispreferably a morpholino methane diphosphonic acid salt that correspondsto the following formula:

This morpholino methane diphosphonic acid salt (MMDA) is also preferredbecause of the fact that it is non-toxic.

The stabilized hydrogen peroxide solution, that can be used asconcentrated hydrogen peroxide solution or used to prepare (lowerconcentration) cleaning solutions according to the invention, preferablycontains hydrogen peroxide in an amount from about 20 to about 70 wt %,more preferably about 30 to about 60 wt %, and most preferably about 35to about 55 wt %, based on the entire solution. It is contemplated thatthe hydrogen peroxide can be introduced in the form of a peroxyhydrateor other agent which release hydrogen peroxide in solution. Preferably,hydrogen peroxide is directly introduced to form the solutions accordingto the invention.

The cyclic amino methane diphosphonic acid compound stabilizer andphosphonic acid based stabilizer are preferably present in amounts andin a ratio sufficient to provide a test solution with a hydrogenperoxide stability of at least about 50% after 16 hours at about 97° C.and a pH of about 9.5 to about 9.6. The test solution is prepared bycombining the stabilized hydrogen peroxide solution, in an amountsufficient to provide the test solution with a starting hydrogenperoxide content of about 3 to 3.5 wt %, with a nonionic/cationicsurfactant blend in an amount of about 5 wt %, based on the weight ofthe test solution, and caustic in an amount to bring the pH of the testsolution to about 9.5 to 9.6. Preferably, the hydrogen peroxidestability is at least about 60% and more preferably at least about 65%.

The cyclic amino methane diphosphonic acid compound stabilizer ispreferably present in an amount of from about 0.01 to about 10 wt %,more preferably about 0.1 to about 5 wt %, and most preferably about 0.3to about 1.5 wt %, based on the amount of hydrogen peroxide. The ratioof cyclic amino methane diphosphonic acid compound stabilizer tophosphonic acid based stabilizer is preferably in the range from about2:1 to about 100,000:1, more preferably about 5:1 to about 5,000:1, andmost preferably about 10:1 to about 500:1.

The stabilized hydrogen peroxide solution (described above) can be usedto prepare a cleaning solution that contains hydrogen peroxide, toprovide a cleaning solution having relatively high hydrogen peroxidestability without the need to add additional stabilizers to the cleaningsolution. The stabilized hydrogen peroxide solution is preferably addedto the cleaning solution in an amount to provide a cleaning solutionhaving an initial hydrogen peroxide concentration of from about 0.1 toabout 20 wt %, more preferably about 0.3 to about 15 wt %, and mostpreferably about 0.5 to about 8 wt %, based on the entire cleaningsolution.

The cleaning solution is preferably prepared by combining the hydrogenperoxide solution with at least one surfactant, water and an alkaliagent in an amount to bring the pH of the cleaning solution to at least6.

It is contemplated that the surfactant can be of a type selected fromthe group consisting nonionic, cationic, anionic, amphoteric,zwitterionic, and combinations thereof. The surfactant is suitablypresent in an amount for about 0.1 to about 15 wt %, preferably about0.3 to about 10 wt %, more preferably about 0.5 to about 8 wt %, basedon the total weight of the cleaning solution.

In one embodiment, the surfactant is preferably of a type selected fromthe group consisting of nonionic, cationic and combinations thereof.Generally any nonionic surfactant material may be used in the inventivecompositions. Practically any hydrophobic compound having a carboxy,hydroxy, amido, or amino group with a free hydrogen attached to thenitrogen can be condensed with an alkylene oxide, especially ethyleneoxide or with the polyhydration product thereof, a polyalkylene glycol,especially polyethylene glycol, to form a water soluble or waterdispersible nonionic surfactant compound. By way of non-limitingexamples, suitable nonionic surfactants which may be used in the presentinvention include polyalkylene oxide condensates of alkyl phenols; thecondensation products of aliphatic alcohols with an alkylene oxide,e.g., an ethylene oxide; primary and secondary linear and branchedalcohol ethoxylates; and alkoxy block copolymers, and in particular,compounds based on ethoxy/propoxy block copolymers. Other examples ofsuitable nonionic surfactants include surfactants sold under the tradenames Berol® 260, Berol® 505, and Berol® 508 (all from Akzo Nobel).

A surfactant can be considered cationic if the charge on the hydrophilicportion of the molecule is positive. Surfactants in which the hydrophilecarries no charge unless the pH is lowered close to neutrality or lower,but which are then cationic (e.g. alkyl amines), are also included inthis group. Suitable cationic surfactants can be easily determined byone skilled in the art. By way of non-limiting examples, suitablecationic surfactants can include compounds containing at least one longcarbon chain hydrophobic group and at least one positively chargednitrogen. In addition, suitable cationic surfactants may contain complexlinkages having more than one cationic nitrogen atom. The cationicsurfactant can include a quaternary ammonium surfactant, such as tallowquaternary ammonium surfactant, such as a tallow amine ethoxylatequaternary ammonium compound. One cationic surfactant suitable for thepresent invention is sold under the trade name Berol® 563SA (from AkzoNobel). Blends of nonionic and cationic surfactants are alsocontemplated. Examples of such blends include surfactants sold under thetrade names Berol® 226SA and Berol® EZ-1 (from Akzo Nobel).

In another embodiment, the surfactant is an anionic surfactant.Generally any anionic surfactant material may be used in the inventivecompositions. By way of non-limiting example, particularly suitableanionic surfactants include: alkali metal salts, ammonium salts, aminesalts, or aminoalcohol salts of one or more of the following compounds(linear and secondary): alcohol sulfates and sulfonates, alcoholphosphates and phosphonates, alkyl sulfates, alkyl ether sulfates,sulfate esters of an alkylphenoxy polyoxyethylene ethanol, alkylmonoglyceride sulfates, alkyl sulfonates, olefin sulfonates, paraffinsulfonates, beta-alkoxy alkane sulfonates, alkylamidoether sulfates,alkylaryl polyether sulfates, monoglyceride sulfates, alkyl ethersulfonates, ethoxylated alkyl sulfonates, alkylaryl sulfonates, alkylbenzene sulfonates, alkylamide sulfonates, alkyl monoglyceridesulfonates, alkyl carboxylates, alkyl sulfoacetates, alkyl ethercarboxylates, alkyl alkoxy carboxylates having 1 to 5 moles of ethyleneoxide, alkyl sulfosuccinates, alkyl ether sulfosuccinates, alkylamidesulfosuccinates, alkyl sulfosuccinamates, octoxynol or nonoxynolphosphates, alkyl phosphates, alkyl ether phosphates, taurates, N-acyltaurates, fatty taurides, fatty acid amide polyoxyethylene sulfates,isethionates, acyl isethionates, and sarcosinates, acyl sarcosinates, ormixtures thereof. Generally, the alkyl or acyl radical in these variouscompounds can include a carbon chain containing 12 to 20 carbon atoms.Examples of specific anionic surfactants suitable for the inventioninclude sodium xylene sulfonate surfactants, as well as naphthalenesulfonate surfactants sold under the trade names Petro BA, Petro AA andPetro ULF (from Akzo Nobel). In one preferred embodiment, the anionicsurfactant has a phenyl sulfonic structure, such as Petro AA.

The pH of the cleaning solution can be adjusted using an alkali agentselected from the group consisting of sodium hydroxide, various ethanolamines, ammonium hydroxide, and mixtures thereof, with sodium hydroxidebeing preferred. Preferably the pH of the cleaning solution is in therange of at least 7 to about 10.5, and more preferably about 8 to about10.

The solutions of the present invention can also optionally include oneor more further constituents which are directed to improving theaesthetic or functional features of the inventive compositions. By wayof non-limiting example such further constituents include one or morebuilders, coloring agents, fragrances and fragrance solubilizers,viscosity modifying agents, other surfactants, other pH adjusting agentsand pH buffers including organic and inorganic salts, opticalbrighteners, opacifying agents, hydrotropes, antifoaming agents,enzymes, anti-spotting agents, anti-oxidants, preservatives, andanti-corrosion agents. When one or more of the optional constituents isadded, i.e., fragrance and/or coloring agents, the esthetic and consumerappeal of the product is often favorably improved. The use and selectionof these optional constituents is well known to those of ordinary skillin the art. When present, the one or more optional constituents presentin the inventive compositions generally do not exceed about 20% wt.,preferably do not exceed 15% wt., and most preferably do not exceed 10%wt.

Certain optional constituents which are nonetheless desirably present inthe inventive compositions are pH adjusting agents and especially pHbuffers. Such pH buffers include many materials which are known to theart and which are conventionally used in hard surface cleaning and/orhard surface disinfecting compositions. By way of non-limiting examplepH adjusting agents include phosphorus containing compounds, monovalentand polyvalent salts such as of silicates, carbonates, and borates,certain acids and bases, tartrates and certain acetates. Furtherexemplary pH adjusting agents include mineral acids, basic compositions,and organic acids, which are typically required in only minor amounts.By way of further non-limiting example pH buffering compositions includethe alkali metal phosphates, polyphosphates, pyrophosphates,triphosphates, tetraphosphates, silicates, metasilicates, polysilicates,carbonates, hydroxides, and mixtures of the same. Certain salts, such asthe alkaline earth phosphates, carbonates, hydroxides, can also functionas buffers. It may also be suitable to use as buffers such materials asaluminosilicates (zeolites), borates, aluminates and certain organicmaterials such as gluconates, succinates, maleates, and their alkalimetal salts. When present, the pH adjusting agent, especially the pHbuffers are present in an amount effective in order to maintain the pHof the inventive composition within a target pH range.

Examples of suitable builders include sodium chloride, EDTA and variousbiodegradable chelating agents. In one embodiment, the builders areselected from the group consisting of organic and inorganic salts.Preferred builders include sodium chloride and a biodegradable chelate,GL-38S (from Akzo Nobel).

In one embodiment, the cleaning solution contains less than 10 ppm ofmetals.

The examples set forth below are for the purpose of illustration and todescribe embodiments of the best mode of the invention at the presenttime. The scope of the invention is not in any way limited by theexamples set forth below.

EXAMPLES

The following examples have been carried out to illustrate preferredembodiments of the invention. These examples include the preparation oftest solutions and hydrogen peroxide stability tests conducted on thetest solutions.

Examples 1-7

Test solutions were prepared using the following stabilizer compounds:1-Hydroxy-ethane diphosphonic acid salt (HEDP) (Dequest 2010),Diethylenetriamine penta(methylenephosphonic acid) salt (DTPMP) (Dequest2060 as acid and Dequest 2066A as the partially neutralized salt), Aminotris(methylenephosphonic acid) salt (ATMP) (Dequest 2000LC) andMorpholino methane diphosphonic acid salt (MMDA) (Budex 5103,manufactured by Buddenheim Chemical as a partially neutralized (50%)sodium salt). Hydrogen peroxide solutions containing about 35% hydrogenperoxide were prepared using the stabilizers and stabilizer combinationsaccording to Table 1 below.

TABLE 1 Stabilizer Combinations (all concentrations in mg/l in 35% H₂O₂)Test # HEDP DTPMP ATMP MMDA 1 250 — — — 2 — — 250 — 3 — 250 — — 4 250 —— 3000 5 — — 250 3000 6 — 250 — 3000 7 — — 250 + 3000 —

Each of the hydrogen peroxide solutions from Table 1 were thenformulated into a test solution comprising 3 to 3.5% H₂O₂, 5% surfactantnonionic/cationic blend (Berol® 226SA from Akzo Nobel), and causticsufficient to bring the pH to 9.5 to 9.6. Samples of each formulationwere then subjected to accelerated stability testing simulating one yearat room temperature (typically 16 hours at 97° C.). The percentage ofinitial oxidizer remaining is recorded as “% stability”.

TABLE 2 Stability Tests Stabilizer Run # Combination % Stability 1 HEDP3.90% 2 ATMP 4.50% 3 DTPMP 16.2% 4 HEDP + MMDA 45.0% 5 ATMP + MMDA 68.1%6 DTPMP + MMDA 66.1% 7 ATMP + ATMP 13.9%

A review of Table 2 reveals that under alkaline conditions with theadded burden of an organic surfactant blend (nonionic/cationic),accelerated stability testing shows a definite stability performanceadvantage to those test solutions with the MMDA. It was also observed(from comparisons of Runs 4-6) that the Run using a phosphonic acidcompound lacking nitrogen in its structure (HEDP) did not fare as wellas the other Runs.

Thus, while there has been disclosed what is presently believed to bethe preferred embodiments of the invention, those skilled in the artwill appreciate that other and further changes and modifications can bemade without departing from the scope or spirit of the invention, and itis intended that all such other changes and modifications are includedwithin the scope of the invention as described in the appended claims.

We claim:
 1. A cleaning solution comprising: (a) from about 0.5 to about8 wt %, based on the entire solution, of hydrogen peroxide; (b) fromabout 0.3 to about 1.5 wt %, based on the amount of hydrogen peroxide,of a first cyclic amino methane diphosphonic acid compound stabilizer;(c) a second phosphonic acid based stabilizer, different from said firstcyclic amino methane diphosphonic acid compound, selected from the groupconsisting of an amino phosphonic acid having three or more phosphonicacid groups in its structure, their salts, and combinations thereof; and(d) a surfactant; wherein the pH of said cleaning solution is at least 7to about 10.5 and the weight ratio of (b) to (c) is in the range fromabout 10:1 to about 500:1.
 2. A solution according to claim 1, whereinsaid first cyclic amino methane diphosphonic acid compound stabilizercorresponds to the following formula:

wherein R₁ is selected from hydrogen, C₁-C₄ alkyl and phenyl; Qrepresents the atoms or chemical bonds necessary to complete a6-membered ring; and X₁ to X₄, independently from each other, areselected from hydrogen, alkali metal and ammonium.
 3. A solutionaccording to claim 2, wherein said surfactant is selected from the groupconsisting of a non-ionic surfactant, a cationic surfactant, andcombinations thereof.
 4. A solution according to claim 2, wherein saidsurfactant is selected from the group consisting of a non-ionicsurfactant, an anionic surfactant, and combinations thereof.
 5. Asolution according to claim 4, wherein said anionic surfactant has aphenyl sulfonic structure.
 6. A solution according to claim 1, whereinthe pH of said cleaning solution is in the range of 8 to
 10. 7. Asolution according to claim 6, wherein said second phosphonic acid basedstabilizer is selected from the group consisting of diethylene triaminepenta(methylene phosphonic) acid, amino tri(methylene phosphonic) acid,and hexamethylene diamine tetra(methylene phosphonic) acid, their salts,and combinations thereof.
 8. A solution according to claim 7, whereinsaid second phosphonic acid based stabilizer is selected from the groupconsisting of diethylene triamine penta(methylene phosphonic) acid,amino tri(methylene phosphonic) acid, their salts, and combinationsthereof.
 9. A solution according to claim 8, wherein said secondphosphonic acid based stabilizer is amino tris(methylenephosphonic acid)salt.